code: def __getitem__(self, key):
      return dict.__getitem__(self, key.lower())
  
file_path: nltk/nltk/sem/lfg.py
imports: from itertools import chain
  from nltk.internals import Counter
label_desc: Use image node_id 3 for calling the FStructure obj's underlying member method code with example usage: obj.__getitem__(key) and returns: dict